Deicing valve



June 18,1946,

L. B. READ DEICING VALVE Filed April 5, 1943 V STATES TENT FICE DEICING VALVE Leland B. Read, South Bend, Ind., assignor to Carter flarbm'etor Corporation, St. Louis, Mo.,

a corporation of Delaware Application April 5, 1943, Serial No. 481,845

1 Claim. i

I buretor, the throttle valve is held slightly open during normal idling to permit the passage of sumcient air to combine with fuel emerging from the idling port to form a properly combustible idling mixture. 1 This air, in passing around the edge of the throttle, expands sharply and, in cool weather before the engine has become fully heated, this expansion frequently causes such coolingof the throttle plate as to cause a formation of ice on the anterior surface and edges thereof and block the idling port. The main object of the present invention is to provide means to prevent or retard the formation of such ice on the throttle and in the vicinity of the idle port.

This object and other more detailed objects hereafter appearing are attained by the structure illustrated in the accompanying drawing in which Fig. 1 is a vertical section through a carburetor embodying the invention and Fig. 2 is a perspective view of the novel throttle valve.

Fig. 3 is a. side view showing the lower part of the carburetor.

The carburetor illustrated is of the downdraft type including an air inlet born I, mixing conduit 2 with venturis 3, and outlet portion 4, flanged as at 5 for attachment to an engine intake manifold 6 above hot spot" portion l.' The air horn is controlled by a choker valve 8 and the outlet portion by a butterfly throttle, generally irfiicated at 9 and plvotally mounted on a shaft through a metering orifice l8 controlled by a metering pin l9 connected to the throttle by means of a lever-20, link 2|, and crank 22 rigid with throttle shaft ill. The main fuel supply passes through inclined passage 23 terminating in a nozzle 24 discharging into the smallest ven turi 3, Idlingfuel is supplied through interconnected idling passage 25, 26 terminating in ports On one end of shaft in there is secured an op-, I

erating arm ll having secured thereto a link l2\ extending to the usual accelerator pedal.

cated at l3. Closing movement of the throttle is adjustably limited to a slightly open idling position by engagement of a screw it, carried by arm A throttle return spring is diagrammatically indill, and a fixed abutment l5. Adjacent the barrel there is provided a chamber 18 within which fuel is maintained at a substantiall constant level by the usual needle valve mechanism (not shown).

and float ll. Fuel is supplied. to the carburetor go when closed. Port 28 is provided with an adlusting screw 29.

The throttle plate is formed of a metal disk til on its upper or anterior side and a disk 3 l, formed of suitable heat insulating material such as Bakelite, on its lower or posterior surface. The disks are secured together and to shaft Ill by means of screws 32. Metallic disk 30 is shown as extendlng slightly beyond lower layer 3| so as to form a sharp edge for cooperating with idling port Zl for metering the fuelsupply during-idling operation.

In operation, air is drawn downwardly through the carburetor barrel and, during idling, sweeps around the edge of the throttle plate to mix with fuel emerging from ports 21 and 28. Because of the sharply decreased pressure posterior to the throttle, this air expands quickly as it passes the throttle, resulting in a cooling action upon the throttle plate. The insulating layer 3| serves to retard the cooling of the metal disk until heat from the engine and hot spot 1 is transmitted to the carburetor.

The exclusive use of all modification as come within the scope of the appended claim is contemplated.

I claim:

In a. carburetor, a mixture conduit, a throttle therein, an idle port discharging adjacent to the edge of said throttle when closed, said throttle being formed of a relativel thick disc of heat insulating material forming the posterior surface thereof, to retard the cooling of said throttle during idling due to the expansion of air passing the same, and a thin, metal disc forming the anterior surface thereof, the edge of said insulating disc being spaced inwardly from the edge of said metal disc closest to said idling port to facilltate varying the discharge from said Port by said metal disc during idling and oil idling operation.

LELAND 8. REM). 

